Adhesives with different chemistries and varying forms have found widespread use in the automotive, aerospace, construction, and biomedical industries. The polymers most often used in adhesives are epoxy, polyurethane, or acrylics. Due to the wide range of uses of adhesives, optimal bonding is needed for a variety of substrates, joint geometries, and applications. When designing an adhesive, the elastic modulus (i.e., stiffness) of both the glue and the substrates being joined must be considered. If the elastic modulus of these materials differs and the joint is subjected to mechanical load, the mismatch in stiffness generates interfacial stresses that can bring about bond failure. There exists a need for adhesives suitable for joining substrates of varying stiffness.